The in vitro assessment of a novel vaping technology

We have developed a novel vaping product (NVP) IS1.0(TT), which utilises a stainless-steel mesh to transfer and vaporise the e-liquid, mitigating some of the potential sources of toxicants that can be generated using the more traditional 'wick and coil' approach. The emissions from IS1.0(TT) have previously been found to have lower levels of toxicants overall when directly compared with a commercial wick and coil e-cig. This current study assessed the toxicological responses to aerosols from this NVP. Responses induced by IS1.0(TT)were compared to those from a 3R4F reference cigarette, using in vitro test methods which included regulatory genetic toxicological assays as well as some more contemporary screening approaches. The experimental conditions were designed to facilitate the testing of aerosol from this vaping product at doses that in most cases greatly exceeded those of the 3R4F comparator showed little to no toxicological responses and demonstrated significantly reduced effects in these in vitro assays when compared to 3R4F. Furthermore, the extreme doses tested in the present study indicate that the toxicant profile of this NVP translates to lower biological activity in vitro, and suggests that the absolute risk hazard level associated with electronic cigarettes can be reduced through continuous improvement as the technology evolves.

Rapid Analysis of Coumarins Using Surface Plasmon Resonance

Coumarin molecules are ubiquitous in nature. Several have come to prominence as potential clinical therapeutic candidates. The principal example is warfarin, which is a very widely prescribed anticoagulant. Other coumarin derivatives, such as aflatoxin B1, are insidious contaminants in crop-derived foodstuffs. Extreme potency is a common feature of all biochemically active coumarins and, thus reliable methods for their rapid and sensitive detection are of paramount importance. Accordingly, this review examines the current methods used in the analysis of these molecules and compares them with immunoassay-based strategies. As a case study, we report on our experiences with using coumarin-specific polyclonal, monoclonal, and recombinant antibodies in conjunction with a surface plasmon resonance-based biosensor for analysis of coumarins. We chart the assay development process and demonstrate high sensitivity and reproducibility that compares favorably with established methodologies.

Establishment and validation of a mental health literacy measurement in Canadian educators

We aim to create the first mental health literacy measure addressing mental health knowledge of educators and assess its psychometric properties. We developed a 30-item multiple choice measure, Mental Health Literacy Tool for Educators (MHL-ED), with experts in both mental health and education. We administered it to educators (n = 909) from 6 Canadian provinces. We analysed the factor structure, internal consistency reliability, construct validity and responsiveness to change of MHL-ED. Factor analysis resulted in 4 factors of MHL-ED addressing: general mental illness and related treatment; assessment and diagnostic tools and treatments; causes and risk factors of mental illness; and epidemiology of mental health and mental illness. MHL-ED demonstrated strong internal consistency reliability. The construct validity was established because the hypothesis was supported that school based mental health professionals scored significantly higher than classroom teachers and school administrators/school support staff; and further MHL-ED scores were positively related with stigma measures. We did not identify floor or ceiling effects of MHL-ED. MHL-ED is reliable and valid to evaluate mental health literacy levels among educators working in junior high and secondary school settings, and may be considered for use in future research in this field.

Time to endoscopy for acute upper gastrointestinal bleeding: Results from a prospective multicentre trainee-led audit

Background

Endoscopy within 24 h of admission (early endoscopy) is a quality standard in acute upper gastrointestinal bleeding (AUGIB). We aimed to audit time to endoscopy outcomes and identify factors affecting delayed endoscopy (>24 h of admission).

Methods

This prospective multicentre audit enrolled patients admitted with AUGIB who underwent inpatient endoscopy between November and December 2017. Analyses were performed to identify factors associated with delayed endoscopy, and to compare patient outcomes, including length of stay and mortality rates, between early and delayed endoscopy groups.

Results

Across 348 patients from 20 centres, the median time to endoscopy was 21.2 h (IQR 12.0-35.7), comprising median admission to referral and referral to endoscopy times of 8.1 h (IQR 3.7-18.1) and 6.7 h (IQR 3.0-23.1), respectively. Early endoscopy was achieved in 58.9%, although this varied by centre (range: 31.0-87.5%, p = 0.002). On multivariable analysis, lower Glasgow-Blatchford score, delayed referral, admissions between 7:00 and 19:00 hours or via the emergency department were independent predictors of delayed endoscopy. Early endoscopy was associated with reduced length of stay (median difference 1 d; p = 0.004), but not 30-d mortality (p = 0.344).

Conclusions

The majority of centres did not meet national standards for time to endoscopy. Strategic initiatives involving acute care services may be necessary to improve this outcome.

In vitro RNA-seq-based toxicogenomics assessment shows reduced biological effect of tobacco heating products when compared to cigarette smoke

The battery of regulatory tests used to evaluate the risk of novel tobacco products such as heated tobacco products (THPs) presents some limitations including a bias towards the apical endpoint tested, and limited information on the mode of action. This is driving a paradigm shift to more holistic systems biology approaches. In this study, we used RNA-sequencing to compare the transcriptomic perturbations following acute exposure of a 3D airway tissue to the aerosols from two commercial THPs and a reference 3R4F cigarette. 2809 RNAs were differentially expressed for the 3R4F treatment and 115 and 2 RNAs for the two THPs (pFDR < 0.05, FC > 1.5), respectively. The relationship between the identified RNA features and gene ontologies were mapped showing a strong association with stress response, xenobiotics metabolism, and COPD-related terms for 3R4F. In contrast, fewer ontologies were found enriched for the THPs aerosols. "Response to wounding" was a common COPD-related term over-represented for the two THPs but at a reduced significance. Quantification of a cytokine panel post-exposure confirmed a pro-inflammatory effect of cigarette smoke but not for THPs. In conclusion, THPs have a reduced impact on gene expression compared to 3R4F.

Discovery of AZD-2098 and AZD-1678, Two Potent and Bioavailable CCR4 Receptor Antagonists

N-(5-Bromo-3-methoxypyrazin-2-yl)-5-chlorothiophene-2-sulfonamide 1 was identified as a hit in a CCR4 receptor antagonist high-throughput screen (HTS) of a subset of the AstraZeneca compound bank. As a hit with a lead-like profile, it was an excellent starting point for a CCR4 receptor antagonist program and enabled the rapid progression through the Lead Identification and Lead Optimization phases resulting in the discovery of two bioavailable CCR4 receptor antagonist candidate drugs.

A novel hybrid tobacco product that delivers a tobacco flavour note with vapour aerosol (Part 2): In vitro biological assessment and comparison with different tobacco-heating products

This study assessed the toxicological and biological responses of aerosols from a novel hybrid tobacco product. Toxicological responses from the hybrid tobacco product were compared to those from a commercially available Tobacco Heating Product (c-THP), a prototype THP (p-THP) and a 3R4F reference cigarette, using in vitro test methods which were outlined as part of a framework to substantiate the risk reduction potential of novel tobacco and nicotine products. Exposure matrices used included total particulate matter (TPM), whole aerosol (WA), and aqueous aerosol extracts (AqE) obtained after machine-puffing the test products under the Health Canada Intense smoking regime. Levels of carbonyls and nicotine in these matrices were measured to understand the aerosol dosimetry of the products. The hybrid tobacco product tested negative across the in vitro assays including mutagenicity, genotoxicity, cytotoxicity, tumour promotion, oxidative stress and endothelial dysfunction. All the THPs tested demonstrated significantly reduced responses in these in vitro assays when compared to 3R4F. The findings suggest these products have the potential for reduced health risks. Further pre-clinical and clinical assessments are required to substantiate the risk reduction of these novel products at individual and population levels.

Reduced biological effect of e-cigarette aerosol compared to cigarette smoke evaluated in vitro using normalized nicotine dose and RNA-seq-based toxicogenomics

Electronic cigarettes (e-cigarettes) use has increased globally and could potentially offer a lower risk alternative to cigarette smoking. Here, we assessed the transcriptional response of a primary 3D airway model acutely exposed to e-cigarette aerosol and cigarette (3R4F) smoke. Aerosols were generated with standard intense smoking regimens with careful consideration for dose by normalizing the exposures to nicotine. Two e-cigarette aerosol dilutions were tested for equivalent and higher nicotine delivery compared to 3R4F. RNA was extracted at 24 hrs and 48 hrs post exposure for RNA-seq. 873 and 205 RNAs were differentially expressed for 3R4F smoke at 24 hrs and 48 hrs using a pFDR < 0.01 and a [fold change] > 2 threshold. 113 RNAs were differentially expressed at the highest dose of e-cigarette aerosol using a looser threshold of pFDR < 0.05, 3 RNAs exceeded a fold change of 2. Geneset enrichment analysis revealed a clear response from lung cancer, inflammation, and fibrosis associated genes after 3R4F smoke exposure. Metabolic/biosynthetic processes, extracellular membrane, apoptosis, and hypoxia were identified for e-cigarette exposures, albeit with a lower confidence score. Based on equivalent or higher nicotine delivery, an acute exposure to e-cigarette aerosol had a reduced impact on gene expression compared to 3R4F smoke exposure in vitro.

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures

Xenobiotic metabolizing enzymes play a key function in the biotransformation of medicines and toxicants by adding functional groups that increase solubility and facilitate excretion. On some occasions those structural modifications lead to the formation of new toxic products. In order to reduce animal testing, chemical risk can be assessed using metabolically competent cells. The expression of metabolic enzymes, however, is not stable over time in many in vitro primary culture systems and is often partial or absent in cell lines. Therefore, the study of medicines, additives, and environmental pollutants metabolism in vitro should ideally be conducted in cell systems where metabolic activity has been characterized. We explain here an approach to measure the activity of a class of metabolic enzymes (Human Phase I) in 2D cell lines and primary 3D cultures using chemical probes and their metabolic products quantifiable by UPLC mass spectrometry and luminometry. The method can be implemented to test the metabolic activity in cell lines and primary cells derived from a variety of tissues.

The comparative in vitro assessment of e-cigarette and cigarette smoke aerosols using the γH2AX assay and applied dose measurements

DNA damage can be caused by a variety of external and internal factors and together with cellular responses, can establish genomic instability through multiple pathways. DNA damage therefore, is considered to play an important role in the aetiology and early stages of carcinogenesis. The DNA-damage inducing potential of tobacco smoke aerosols in vitro has been extensively investigated; however, the ability of e-cigarette aerosols to induce DNA damage has not been extensively investigated. E-cigarette use has grown globally in recent years and the health implications of long term e-cigarette use are still unclear. Therefore, this study has assessed the induction of double-strand DNA damage in vitro using human lung epithelial cells to e-cigarette aerosols from two different product variants (a "cigalike" and a closed "modular" system) and cigarette smoke. A Vitrocell^® VC 10 aerosol exposure system was used to generate and dilute cigarette smoke and e-cigarette aerosols, which were delivered to human bronchial epithelial cells (BEAS-2Bs) housed at the air-liquid-interface (ALI) for up to 120min exposure (diluting airflow, 0.25-1L/min). Following exposure, cells were immediately fixed, incubated with primary (0.1% γH2AX antibody in PBS) and secondary antibodies (DyLight™ 549 conjugated goat anti-mouse IgG) containing Hoechst dye DNA staining solution (0.2% secondary antibody and 0.01% Hoechst in PBS), and finally screened using the Cellomics Arrayscan VTI platform. The results from this study demonstrate a clear DNA damage-induced dose response with increasing smoke concentrations up to cytotoxic levels. In contrast, e-cigarette aerosols from two product variants did not induce DNA damage at equivalent to or greater than doses of cigarette smoke aerosol. In this study dosimetry approaches were used to contextualize exposure, define exposure conditions and facilitate comparisons between cigarette smoke and e-cigarette aerosols. Quartz crystal microbalance (QCM) technology and quantified nicotine delivery were both assessed at the exposure interface. Nicotine was eluted from the QCM surface to give a quantifiable measure of exposure to support deposited mass. Dose measured as deposited mass (μg/cm²) and nicotine (ng/mL) demonstrated that in vitro e-cigarette exposures were conducted at doses up to 12-28 fold to that of cigarette smoke and demonstrated a consistent negative finding.

Application of dosimetry tools for the assessment of e-cigarette aerosol and cigarette smoke generated on two different in vitro exposure systems

The diluted aerosols from a cigarette (3R4F) and an e-cigarette (Vype ePen) were compared in two commercially available in vitro exposure systems: the Borgwaldt RM20S and Vitrocell VC10. Dosimetry was assessed by measuring deposited aerosol mass in the exposure chambers via quartz crystal microbalances, followed by quantification of deposited nicotine on their surface. The two exposure systems were shown to generate the same aerosols (pre-dilution) within analytically quantified nicotine concentration levels (p = 0.105). The dosimetry methods employed enabled assessment of the diluted aerosol at the exposure interface. At a common dilution, the per puff e-cigarette aerosol deposited mass was greater than cigarette smoke. At four dilutions, the RM20S produced deposited mass ranging 0.1–0.5 µg/cm²/puff for cigarette and 0.1–0.9 µg/cm²/puff for e-cigarette; the VC10 ranged 0.4–2.1 µg/cm²/puff for cigarette and 0.3–3.3 µg/cm²/puff for e-cigarette. In contrast nicotine delivery was much greater from the cigarette than from the e-cigarette at a common dilution, but consistent with the differing nicotine percentages in the respective aerosols. On the RM20S, nicotine ranged 2.5–16.8 ng/cm²/puff for the cigarette and 1.2–5.6 ng/cm²/puff for the e-cigarette. On the VC10, nicotine concentration ranged 10.0–93.9 ng/cm²/puff for the cigarette and 4.0–12.3 ng/cm²/puff for the e-cigarette. The deposited aerosol from a conventional cigarette and an e-cigarette in vitro are compositionally different; this emphasises the importance of understanding and characterising different product aerosols using dosimetry tools. This will enable easier extrapolation and comparison of pre-clinical data and consumer use studies, to help further explore the reduced risk potential of next generation nicotine products.Graphical abstract

Gender Differences in Aortic Neck Morphology in Patients with Abdominal Aortic Aneurysms Undergoing Elective Endovascular Aneurysm Repair

BACKGROUND

Previous studies have demonstrated that women tend to have adverse aortic neck morphology leading to exclusion of some women from undergoing endovascular aneurysm repair (EVAR). The objective of this study is to investigate differences in aortic neck morphology in men versus women, changes in the neck morphology and sac behavior after EVAR, and investigate how these features may influence outcomes.

METHODS

We conducted a retrospective review of elective EVARs (2004-2013). We excluded patients who underwent elective EVAR with no postoperative imaging available and those patients with fenestrated repairs. Using TeraRecon and volumetric analysis, several features were investigated. These included percent thrombus, shape, length, angulation of the neck, and changes in neck and abdominal aortic aneurysm diameter.

RESULTS

A total of 146 patients were found to meet inclusion criteria (115 men and 31 women) with similar baseline characteristics. Neck angulation was greater in women (23.9° vs. 13.5°; P < 0.028). The percent thrombus in women was higher than men (35.4% vs. 31%; P < 0.02). Abdominal aneurysm's were smaller in women at 1 year (4.2 cm vs. 5.1 cm; P < 0.002), and secondary interventions were higher in men (11.3% vs. 0%; P < 0.05). Other features such as neck shape, changes in neck diameter, neck length, and percent oversizing of graft where not statistically different between genders.

CONCLUSIONS

Gender differences in neck characteristics and changes in neck morphology do not appear to adversely affect EVAR outcomes. Longer follow-up is necessary to further assess whether these findings are clinically durable.

Weight loss outcomes among patients referred after primary bariatric procedure

BACKGROUND

Bariatric patients may not always obtain long-term care by their primary surgeon. Our aim was to evaluate weight loss outcomes in patients who had surgery elsewhere.

METHODS

We conducted a retrospective analysis. Postreferral management included nonsurgical, revision, or conversion. Primary outcomes were percent excess weight loss (%EWL) overall, according to original operation, and based on postreferral management.

RESULTS

Between 2001 and 2013, there were 569 patients. Mean follow-up was 3.1 years. Management was 42% nonsurgical, 41% revision, and 17% conversion. Overall, mean %EWL was 45.3%. Based on original surgery type, %EWL was 41.2% for adjustable gastric banding vs 58.3% for Roux-en-Y gastric bypass (P ≤ .0001). Management affected %EWL (41.2% nonsurgical vs 45.3% revision vs 55.1% conversion, P ≤ .0001).

CONCLUSIONS

Patients referred after bariatric surgery can achieve satisfactory weight loss. This differs based on surgery type and management strategy.